Safety and side effects of sustained-release niacin.
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Cholesterol↗
Biomedical subjects
M Weiner
Publications and source records attributed to M Weiner.
Esophageal balloon cytology and subsequent risk of esophageal and gastric-cardia cancer in a high-risk Chinese population.
Linxian, China has some of the highest rates of esophageal/gastric cardia cancer in the world. In 1983, esophageal balloon cytology screening was performed in 3 communes in northern Linxian. Of the participants, 10,066 with no evidence of cancer were followed prospectively for 7 1/2 years to evaluate the ability of the initial cytologic diagnoses to identify individuals at increased risk for developing cancer of the esophagus or gastric cardia. A total of 747 incident cases of esophageal or cardia cancer and 322 deaths due to these tumors were identified during the follow-up period and used in this analysis. The risks for esophageal or cardia cancer incidence and mortality increased in parallel with the presumed severity of the 1983 Chinese cytologic diagnoses. After adjusting for potential confounding factors, relative risks for esophageal or cardia cancer incidence, by initial cytologic diagnosis, were normal = 1.00 (reference), hyperplasia = 1.25, dysplasia 1 = 2.20, dysplasia 2 = 4.22 and near-cancer = 5.96. Our results suggest that esophageal balloon cytology, as performed and interpreted in Linxian in 1983, successfully identified individuals at increased risk for developing cancer of the esophagus or gastric cardia.
Age Factors↗
Reversal of megaduodenum and duodenal dysmotility associated with improvement in nutritional status in primary anorexia nervosa.
Anorexia nervosa is considered one type of eating disorder that may result in severe malnutrition. Patients with this disorder commonly complain of postprandial nausea, abdominal pain, and distension. We describe the radiologic and motility abnormalities associated with anorexia nervosa in a 21-year-old female. Barium gastrointestinal series demonstrated marked dilation of the duodenum, with prolongation of intestinal transit. A 4-hr fasting gastroduodenal motility study showed no propagating migrating motor complexes (MMC). Prolonged, but nonpropagating, bursts of high-amplitude phasic and tonic contractions were seen in the duodenum. In contrast, antral contractions were of low amplitude and esophageal motor function was normal. Metoclopramide and edrophonium caused an increase in gastroduodenal motor activity, but increased contractions were not associated with symptoms. Following a renutrition program that raised the patient's weight from 64 to 80% of her ideal body weight, the radiographic abnormalities and gastrointestinal dysmotility resolved completely. These observations suggest that anorexia-associated gastrointestinal motor dysfunctions are a consequence, not the cause of the generalized protein-calorie malnutrition associated with anorexia nervosa. The facts that motility in different parts of the gut is affected to different degrees and that gastric and duodenal muscle responds normally to exogenous stimulation argue against a generalized myogenic dysfunction and, rather, point to a reversible dysfunction of neural regulation.
Adult↗
Conjunctival orbital cyst.
A 61-year-old woman had gradual onset of ptosis and painless proptosis of her left eye of 1-year duration. Orbital computed tomography (CT) showed a well-circumscribed superior nasal orbital tumor with uniform density. The mass was removed by anterior orbitotomy and histopathologically diagnosed as a conjunctival cyst. Recent reports have increased awareness of this entity. This case typifies findings of conjunctival orbital cysts. These cysts should be considered when a differential diagnosis is formulated for orbital tumors with a similar presentation.
Blepharoptosis↗
Concepts of "tissue PO2" in relation to O2 delivery.
Resistance to O2 diffusion is reflected in the difference in pO2 between O2 reservoirs of hemoglobin (Hb) and myoglobin. The very low normal myocyte pO2 (less than one torr but adequate for optimal oxidative ATP synthesis) compared to venous pO2 indicates that blood does not achieve equilibrium with tissue during its passage through capillaries. In the lung, diffusion rate of O2 from alveolus to capillary is normally sufficient to achieve essential equilibrium. However, system-wide capillary pathology and reduced Hb saturation has been observed with distal local ischemia. In peripheral vascular disease (PVD) patients, we found a mean arterial pO2 of 77 torr (normal over 90 torr). Classical concepts based on "tissue pO2" values derived from venous blood or oxygen electrodes inserted into tissue need re-evaluation. Readings of O2 electrodes moved through tissue range widely from intracapillary levels down toward intracellular levels and do not reflect the pO2 of any particular site. Intravenous pO2 is the result of residual O2 after incomplete diffusion out of capillaries during transit through a tissue, and is not an equilibrium value with some tissue pool. The effect of HbO2 p50 on oxygen release during the passage of blood through a capillary bed, generally judged on the basis of percentage percent saturation at "tissue pO2", should be judged on the basis of the change in pO2 (the diffusion driving force) associated with a particular degree of HbO2 saturation at a particular p50. The thesis that O2 diffusion rate is a major determinant of oxygen delivery is supported by pO2 responses to treatment of PVD that does not alter blood flow or p50.
Animals↗
The airway in the obstetrical patient.
Airway management of the parturient has serious implications for the anesthetist. Meticulous patient evaluation and preparation is essential. A management plan that can be implemented in the event of failed intubation should be familiar to all anesthetists who are involved in obstetrical anesthesia.
Anesthesia, Obstetrical↗
A mutational analysis of the polypyrimidine tract of introns. Effects of sequence differences in pyrimidine tracts on splicing.
The polypyrimidine (py) tract of introns is required for efficient spliceosome assembly and splicing of pre-mRNAs. A detailed mutational analysis of the py tract of an adenovirus 2 intron was carried out. Utilizing a "precursor in pieces" vector system, it was possible to synthesize py tract mutant pre-mRNAs that were otherwise identical. The mutant pre-mRNAs that were otherwise identical. The mutant pre-mRNAs were analyzed for in vitro splicing, for formation of splicing complexes, and for binding to proteins in the HeLa nuclear extract. Chimeric pre-mRNAs that contained the yeast branch point consensus sequence (UAC-UAAC) and altered py tracts were also analyzed. Mutational analysis showed the following. First, any mutation in the py tract that affected splicing did so by interferring with complex A formation in spliceosome assembly. Second, introduction of purines into the py tract is detrimental only if the length of the tract is shortened and if there is a reduction in the number of consecutive uracil residues. Third, uracil and cytosine do not have equivalent functions in the py tract. Our results with chimeric pre-mRNAs also show that a strong py tract can partially replace a weak branch point sequence and a strong branch point sequence can partially replace a weak py tract. Finally, the one surprising finding obtained when examining protein binding was that a mutant pre-mRNA did not bind to heterogeneous nuclear ribonucleoprotein C proteins and yet spliced close to wild type level.
Adenoviruses, Human↗
[Unusual treatment for myasthenia gravis associated with asthma].
Abnormal antibody production is now recognized as the basis of many diseases, among them myasthenia gravis (MG) and a variant of bronchial asthma. It is not unusual to find 2 or even more of these diseases in the same patient. A patient in whom both MG and bronchial asthma were diagnosed is presented. In both diseases the respiratory muscles are mechanically disadvantaged, which may result in severe dyspnea. In our case, despite specific treatment for both diseases severe attacks of dyspnea still occurred. Specific inspiratory muscle training was followed by significant clinical improvement. There was indirect evidence that respiratory muscles can be trained in patients with MG. Thus, patients with MG with respiratory muscle involvement may benefit from respiratory muscle training.
Asthma↗
Requirement of cellular uptake for adenosine inhibition of p-nitrophenol glucuronidation in isolated rat hepatocytes.
Adenosine (ADO) has been shown previously to inhibit p-nitrophenol glucuronidation in a concentration-dependent manner when concurrently incubated in isolated rat hepatocytes for 30-60 min. In the current study, preincubation of ADO (500 microM) in isolated hepatocytes for 30 min prior to addition of 100 microM p-nitrophenol resulted in a greater inhibition of glucuronidation when compared to that without preincubation (80 vs 50% inhibition). The inhibitory effect of 250 microM ADO on glucuronidation was decreased from 60 to 10% in the presence of the ADO transport inhibitor nitrobenzyl thioinosine during the 30-min preincubation period. Without prior incubation, 100 microM dibutyryl cyclic AMP (DBcAMP) produced an inhibition of glucuronidation similar to that of 500 microM ADO. In contrast to ADO, there was no significant difference in the inhibitory effect of DBcAMP on p-nitrophenol glucuronidation with or without a 30-min preincubation. Thus, DBcAMP and ADO appear to inhibit glucuronidation through different mechanisms. Furthermore, these results indicate that the inhibitory effect of ADO on p-nitrophenol glucuronidation is dependent to a large degree on the cellular uptake of ADO into hepatocytes, while a portion of the inhibitory effect may arise from the generation of intracellular cyclic AMP.
Adenosine↗
[Inspiratory muscle training combined with general exercise reconditioning in chronic obstructive pulmonary disease].
In a controlled clinical trial, we compared the effect of 6 months of specific inspiratory muscle training combined with general exercise reconditioning, with that of general exercise reconditioning alone. We measured the effects of the 2 regimens on inspiratory muscle strength, endurance, and exercise performance in patients with chronic obstructive pulmonary disease (COPD), 2 groups of 10 patients each. Inspiratory muscle strength (expressed as the PImax at RV) increased significantly from 43.2 +/- 3.0 to 67.8 +/- 2.9 cm H2O (p < 0.0001) and respiratory muscle endurance (expressed as the relationship between PmPeak, the pressure achieved with the heaviest load tolerated for at least 60 sec, and PI max) increased significantly from 60.2 +/- 2.5 to 85.6 +/- 2.8% (p < 0.001) in the first group (combined treatment). After the 6-month training period, in both groups there were significant increases in 12-minute walk and endurance work time at 2/3 of Wmax (maximal work each subject achieved on a progressive bicycle exercise test of maximum work load). However, those in the first group showed significantly greater improvement in distance walked and endurance time than the others. We conclude that specific inspiratory muscle training for 6 months improves inspiratory muscle strength and endurance in patients with COPD. This training, combined with general exercise reconditioning, also results in improvement in exercise tolerance significantly greater than that of general exercise reconditioning alone.
Breathing Exercises↗
Airway management in obstetric anesthesia.
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Journal Article↗
The revival of nitric acid for the treatment of anogenital warts.
The destruction of small lesions by tissue denaturation (fixation) rather than erosion (acid hydrolysis) is accomplished by nitric acid of moderate strength in which nitric acid reduction products are generated by nitric acid oxidation of added organic acids. Such solutions show a temperature-dependent increase or loss of nitrite during storage, with loss of therapeutic activity when nitrite levels decrease after storage at cooler temperatures. Use of a preparation technique that completely consumes all the oxidizable organic components added to generate nitrite results in a stable preparation that is effective, well tolerated, and convenient in the treatment of anogenital warts (condylomata acuminata). Of 50 patients monitored after treatment with a 6.6 mol/L nitric acid preparation with no residual oxidizable organic agents, results were good in 39 patients, satisfactory in four patients, and unsatisfactory in seven patients. These observations lead to a simplified stable preparation of modest nitric acid concentration with adequate nitrate reduction products for efficacy in the topical ablation of small skin lesions such as condylomata acuminata.
Acids↗
Oxygen transport in peripheral arterial occlusive disease: effects of calf blood dialysate.
The obvious relationship of arterial blood flow to tissue hypoxia has led to the relative neglect of secondary mechanisms that might influence the functional and morphologic consequences of major vessel obstruction. Oxygen diffusion through capillaries, both locally and systemically, may be disturbed in subjects with chronic local ischemia. Follow-up data after a double-blind, placebo-controlled evaluation of the effect of treatment with a calf blood dialysate confirm that such treatment may alleviate the consequences of peripheral arterial obstructive disease even though there is no improvement in blood flow through the arterial system involved.
Animals↗
The effect of corticosteroids on inspiratory muscle performance in humans.
Functional alterations in the inspiratory muscles were evaluated in patients receiving corticosteroids for diseases other than respiratory. Inspiratory muscle strength, as expressed by the maximal inspiratory mouth pressure (PImax), and inspiratory muscle endurance (PmPeak/PImax), using a pressure threshold breathing device, were evaluated in eight patients with normal pulmonary and inspiratory muscle functions (two patients with rapidly progressive glomerulonephritis, two with glomerulonephritis with minimal changes, two with idiopathic thrombocytopenic purpura, and two with subacute thyroiditis). There was a gradual decrease in both inspiratory muscle strength and endurance following corticosteroid administration. After 8 weeks of treatment PmPeak/PImax decreased from 84.4 +/- 2.4 to 67.9 +/- 3.1 percent (p < 0.001), while inspiratory muscle strength dropped from 126.9 +/- 9.6 to 86.5 +/- 7.4 cm H2O (p < 0.005). Gradual steroid dosage tapering resulted in marked improvement in both strength and endurance; the inspiratory muscle strength rose significantly to 112.2 +/- 8.1 cm H2O (p < 0.0005) when steroid treatment was stopped, and even more significantly 6 months later (to 123.1 +/- 8.1 cm H2O [p < 0.0001]), and the PmPeak/PImax rose to 60.6 +/- 3.4 percent (p < 0.001) and to 74.7 +/- 3.2 percent (p < 0.0001), respectively. We conclude that corticosteroids have a significant deteriorating effect on respiratory muscle function in humans. This weakness is reversible while tapering steroid dosage. Steroid therapy should be reconsidered in patients with underlying lung disease.
Adolescent↗
Thallium-201 scintigraphy for assessment of a gallium-67-avid mediastinal mass following therapy for Hodgkin's disease.
Differentiating thymic rebound from recurrent tumor may be difficult in pediatric patients following chemotherapy for Hodgkin's disease. We present a patient who had both a negative 67Ga scan and computed tomography (CT) of the chest at diagnosis and demonstrated gallium avidity and CT evidence of a new mediastinal mass at the completion of chemotherapy. There was, however, no other clinical or laboratory evidence of disease recurrence. Thallium-201 imaging was subsequently performed and demonstrated no significant radionuclide accumulation within this anterior mediastinal mass. CT shows only the presence of a mass, but not it's nature. Gallium-67 scintigraphy, while used widely as an indicator of tumor viability, may demonstrate increased uptake in cases of thymic rebound. Thallium-201 imaging has previously been shown to demonstrate increased uptake in mediastinal malignancy. Conversely, no significant mediastinal uptake of 201Tl, as in this case, provides additional supportive evidence for a benign mediastinal entity such as thymic rebound.
Antineoplastic Combined Chemotherapy Protocols↗
[Hemodynamics and sleep structure in attempted weaning after nCPAP ventilation therapy of obstructive sleep apnea syndrome].
nCPAP (continuous positive airway pressure) treatment is presently the standard therapy in marked obstructive sleep apnoea syndrome. Fundamentally, this is a long-term treatment. Various authors have been making different recommendations in respect of the frequency of application, based partly only on the patient's individual pattern of complaints and symptoms. Our study aimed at examining the short-term nocturnal effects of discontinuing the treatment course in 12 patients, using polysomnography as a diagnostic tool. Results showed that directly after discontinuation of therapy the sleep structure, respiration during sleep and the nocturnal blood pressure pattern returned to baseline findings. It is concluded from this that nCPAP treatment should be strictly adhered to every night to minimise the risk of cardiovascular complications in the patients concerned.
Adult↗
The application of newer concepts of oxygen transport to the evaluation of the potential utility of reduced Hb-O2 affinity.
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Animals↗
Sickle cells modified by an osmotic pulse in the presence of inositol hexaphosphate have decreased intracellular hemoglobin concentration and decreased in vitro sickling without prolonged in vivo survival.
An osmotic pulse was used to modify red blood cells (RBC) from two patients with sickle cell disease, resulting in an increased volume and decreased hemoglobin content. This treatment yielded cells which were divided into two populations, one in which RBC had markedly decreased hemoglobin concentration and another in which the cells appeared to be unmodified. Morphological sickling at low oxygen partial pressure was markedly decreased. However, there was no evidence for increased RBC lifespan when the 51Cr-labeled, modified cells were reinfused.
Anemia, Sickle Cell↗